text: Supramolecular containers do not only have an application in catalysis but also in the opposite, namely, inhibition. A container molecule could encapsulate a guest molecule and thus subsequently renders the guest unreactive. A mechanism of inhibition could either be that the substrate is completely isolated from the reagent or that the container molecule destabilize the transition state of the reaction.
  Nitschke and coworkers invented a self-assembly ML supramolecular host with a tetrahedral hydrophobic cavity that can encapsulate white phosphorus. Pyrophoric phosphorus, which could self-combust upon contact with air, is rendered air-stable within the cavity. Even though the hole in the cavity is large enough for an oxygen molecule to enter, the transition state of the combustion is too large to fit within the small cage cavity.